BROOMFIELD, Colo. –The Colorado Department of Agriculture’s State Veterinarian’s Office currently has 184 locations under quarantine after horses and cows tested positive for Vesicular Stomatitis (VS). The quarantines are located in Adams, Boulder, Broomfield, Douglas, El Paso, Jefferson, Larimer, and Weld counties; results on additional tests in these and other counties are pending. VS can be painful for animals and costly to their owners. The virus typically causes oral blisters and sores that can be painful causing difficulty in eating and drinking. In Colorado there are 201 horses and 3 cows that tested positive for VS.

“The Colorado Department of Agriculture is not recommending events be cancelled; instead, we are recommending that events and livestock owners take extra caution to control flies,” said State Veterinarian, Dr. Keith Roehr. “Livestock owners should not grow weary in doing well concerning insect control. There is some evidence that fly control practices have been an effective prevention tool in this present VS outbreak.”

Veterinarians and livestock owners who suspect an animal may have VS or any other vesicular disease should immediately contact State or federal animal health authorities. Livestock with clinical signs of VS are isolated until they are healed and determined to be of no further threat for disease spread. There are no USDA approved vaccines for VS.

While rare, human cases of VS can occur, usually among those who handle infected animals. VS in humans can cause flu-like symptoms and only rarely includes lesions or blisters.

Colorado State University – Veterinary Diagnostic Lab (CSU-VDL) has assisted CDA and USDA in responding to the VS outbreak by acting as a sample drop-off site in which practicing veterinarians can drop off samples from possible VS cases. The samples are then packaged and submitted to the USDA National Veterinary Services Laboratory in Ames, Iowa by state or federal personnel. CSU-VDL’s involvement has helped us to be more efficient in our response activities.

CSU Online Presentation

Colorado State University hosted an interactive online discussion about VS last Thursday. The presentation can be viewed at http://csu-cvmbs.colostate.edu/vth/Pages/vesicular-stomatitis-presentation.aspx and will help all interested horse and livestock owners understand the disease, its transmission, reasons for quarantine, economic concerns during the current outbreak, the fate of horse shows and events, disease treatment and preventative measures.

Vesicular Stomatitis (VS) Signs and Transmission

VS susceptible species include horses, mules, cattle, bison, sheep, goats, pigs, and camelids. The clinical signs of the disease include vesicles, erosions and sloughing of the skin on the muzzle, tongue, ears, teats, groin area, and above the hooves of susceptible livestock. Vesicles are usually only seen early in the course of the disease. The transmission of vesicular stomatitis is not completely understood but components include insect vectors, mechanical transmission, and livestock movement.

“The State Veterinarian’s Office is not recommending that livestock shows be cancelled. Instead, it is more important to consider certificates of veterinary inspection prior to or on site observations at entry into events and then insect control measures during before during and after events occur,” said Roehr. “If event organizers have questions, they can contact our office.”

Tips for Event Organizers and Livestock Owners:

Strict fly control is an important factor to inhibit the transmission of the disease.

Colorado veterinarians and livestock owners should contact the state of destination when moving livestock interstate to ensure that all import requirements are met. A list of contact information for all state veterinarians’ offices is available at www.colorado.gov/ag/animals and click on “Import Requirements.”

Colorado fairs, livestock exhibitions, and rodeos may institute new entry requirements based on the extent and severity of the current VS outbreak. Certificates of Veterinary Inspection issued within 2-5 days prior to an event can beneficial to reduce risks. Be sure to stay informed of any new livestock event requirements.

During an event, important VS disease prevention procedures include minimizing the sharing of water and feed/equipment, applying insect repellent daily (especially to the animals ears), and closely observing animals for signs of VS.

If moving livestock internationally please contact the USDA APHIS VS Colorado office at 303-231-5385 to determine if there are any movement restrictions or testing requirements for VSV.

Important Points for Veterinarians

Any vesicular disease of livestock is reportable to the State Veterinarian’s Office in Colorado – to report call 303-869-9130. If after-hours, call the same number to obtain the phone number of the staff veterinarian on call.

Since VS is considered a foreign animal disease, any case with clinical signs consistent with VS will warrant an investigation by a state or federal foreign animal disease diagnostician (FADD).

When VS is suspected, the FADD will gather the epidemiological information, take the necessary blood samples, collect the necessary fluid or tissue from the lesions, and inform the owners and the referring veterinarian as to necessary bio-security and movement restrictions